Calymperes fasciculatum Dozy & Molkenboer 1856

Plants of Calymperes fasciculatum with contorted leaves somewhat resemble those of C. levyanum var. hainanense, C. lonchophyllum, and C. serratum in the field but are easily distinguished under the microscope by their acuminate leaves with long excurrent costae. The obvious stems and appressed, secund leaves are good field characters for most specimens. This species is locally common in some places on Hainan Island. Calymperes fasciculatum has previously been reported from China under the name Calymperes johanniswinkleri Broth. var. hasegawae (Tak. & Iwats.) Iwats., a synonym.

Plants dark green, unbranched, in low tufts and dense cushions. Stems elongate; rhizoids glossy blackish red. Leaves essentially monomorphic, mostly appressed and secund when dry, sometimes contorted, spreading-patent when wet, broadly to narrowly linear-acuminate above broader base, broadest at shoulders, to 6 mm long, axillary hairs scanty; costa of distal leaves often long-excurrent and with narrow toothed wings of laminae; cells of upper laminae isodiametric to transversely elongate, smooth abaxially, smooth to bulging or minutely papillose adaxially; margins thickened, toothed in two rows distally; teniolae lacking; distal cells of cancellinae sharply demarcated from adjacent green cells of upper laminae. Gemmae frequent, adaxially located on tip of costa.

Distribution: widespread from Burma and Sri Lanka eastward through tropical Asia, China, Japan, Malaysia, and Oceania.

Habitat: uncommon but sometimes locally abundant on tree trunks, bases, and rock in forests at medium to rather high elevations, 600–1540 m.